Knowledge of valves

Valve port has a wide range of uses and types The classification of valves is becoming more and more difficult. In order to better understand valve products, Duoyi company classifies common valves The types of valves are classified according to the actual working conditions on site. Some of them are selected by the manufacturer and used under special circumstances. Different purposes and action principles are different. The general can be divided into two categories:

The first type of automatic valve: a valve that acts by itself depending on the capacity of the medium (liquid and gas). Such as check valve, safety valve, regulating valve, drain valve, pressure reducing valve, etc. The second type of driving valve: the valves that operate with the help of manual, electric, hydraulic and pneumatic, such as lift valve, ball valve, gate valve, stop valve, throttle valve, plug valve, etc.

At present, the most commonly used valve classification methods at home and abroad are as follows:

1. according to the structural features, it can be divided according to the moving direction of the closing part relative to the valve seat:

 Truncated gate shape: the closing part moves along the center of the valve seat.

 Gate shape: the closing part moves along the center of the vertical valve seat.

 Cock and ball: the closing part is a plunger or ball, which rotates around its own centerline.

 Swing type; The closing member rotates around the shaft outside the valve seat.

Dished shape: the ring of the closing part rotates around the shaft in the valve seat.

Slide valve shape: the closing part slides in the direction perpendicular to the channel.

2. According to the driving type, it can be divided into:

Electric: driven by motor or other electrical devices.

Hydraulic: driven by (water, oil).

Pneumatic; Use compressed air to drive the valve to open and close.

Manual: with the help of hand wheel, handle, lever or sprocket, there is manual drive. When the transmission torque is large, worm gear, gear and other reduction devices are installed.

3. According to the purpose, the valve [] can be divided into:

Disconnection: used to connect or cut off pipeline media, such as stop valve, gate valve, ball valve, butterfly valve, etc

Check valve: used to prevent medium backflow, such as check valve.

Regulating: used to regulate the pressure and flow of medium, such as regulating valve and pressure reducing valve.

For distribution: change the medium flow direction and distribute the medium, such as three-way cock, distribution valve, slide valve, etc.

Safety valve: when the medium pressure exceeds the specified value, it will discharge excess medium to ensure the safety of pipeline system and equipment, such as safety valve and emergency valve. 6. Other special purposes: such as drain valve, vent valve, blowdown valve, etc.